In certain leading edge technological applications such as the operation of free electron lasers and the like, there exists the need to be able to safely handle very high voltages, on the order of above 500,000 volts, in, for example, power supplies and the like. In such applications, load resistors capable of handling such voltages are a necessary requirement. In such applications, the presence of electrical current on the order of 2 amps or higher is also quite possible.
Currently there are only a few commercially available options for resistors capable of handling such loads. Among these are solid carbon resistors and high resistance metal alloy load banks. While solid carbon resistors are capable of handling such loads, they are very expensive to construct, require long lead times to obtain, are not adjustable to ohmic values other than those for which they were designed and built, i. e. not flexible, and if high voltage flash-over or arcing occurs significant damage will be inflicted and the costly resistor will have to be replaced because repair is not normally an option. Metal alloy banks demonstrate similar shortcomings in that they are even more expensive to construct, require long lead times to obtain, are not adjustable to ohmic values other than those for which they were designed and built and furthermore, are usually designed to handle larger current loads at much lower operating voltages than those encountered in, for example, the operation of free electron lasers as just described. Thus, while such prior art devices may meet the needs of certain applications, their high cost, relative inflexibility in terms of modification for load variation, and their relative inability to be readily repaired make them inappropriate for use in high voltage applications that may require voltage or amperage handling variation and could result in damage to the resistor.
Thus, there exists a need for a relatively inexpensive resistor system capable of handling very high voltages on the order of hundreds of thousands of volts, which resistor system possesses the ability to be readily modified to change is voltage/amperage handling characteristics and which can be readily repaired in the case of high voltage flash-over or arcing event.